怎么使Model S的价格便宜一半？特斯拉有了新计划

    参加聚会的电极颗粒

    达恩解释说，大家可以把电池电极想象成一个房间，电极中的大量颗粒就像在房间里聚会的人。如果这些人都突然变得很胖，房间里就装不下那么多人了。

    他说：“如果大家都挤了进去，然后他们都变得有400磅重，那就会带来大麻烦。”

    用硅制作所有电极颗粒就会出现这样的情景。但如果房间里只有一些人变胖，问题就不那么大，大家可以挪动一下，给胖人留下足够的空间。

    达恩指出：“最初只添加少量硅的原因就在这里。”

    但使用硅材料的问题还不止于此。我们还用上面的比喻来解释，大家可以想象一下，这些胖人（或者说较大的电极颗粒）在充电时变瘦，放电时再次变胖。其体积的大幅变化会引发另一个问题。所有硅电极颗粒都浸泡在电解液中，当它们变大时，就会不断拉伸包裹着它们的保护膜；当它们缩小时，保护膜则有可能脱落，这可能影响到电池的使用寿命。

    达恩说，这种情况意味着用的硅越多，电池的寿命就越难保证。

    这就是目前电池厂商和研究人员的处境。

    达恩说：“眼下只能加一点点硅，就像洒魔粉那样，这样的量还可以接受。几年后，硅会用得越来越多。这是件好事，因为它意味着这些产品会越变越好。”

    达恩的研究团队打算既提高锂离子电池的能源密度，又延长它的使用寿命。这或许有助于降低电动汽车和电网能源存储的成本。但正在这么做的不光是他们。达恩指出：“世界上有好些公司都在往阴极里添加硅。不仅仅是为特斯拉提供电池的松下，三星和其他一些公司也在这样做。”

    萨姆·杰斐曾在清洁能源研究和分析机构Navigant Research长期从事分析工作，现在他是初创公司Cygnus Energy Storage的首席执行官。他认为，目前大多数电池中的硅含量都非常低，包括消费电子产品使用的电池。

    问题在于特斯拉用了多少硅。杰斐说，业界标准是硅占电池原材料的1-3%。他认为特斯拉已经找到了提高硅含量的办法。

    他指出：“特斯拉已经显著改变了电池的能源密度，而且公开宣称是硅让他们做到了这一点，这让我觉得他们在提高电池硅含量方面已经取得了进展。当然，现在这只是猜测。”

    Model X和作为供应商的特斯拉

    车辆估值及汽车市场研究机构Kelley Blue Book高级分析师卡尔•布劳尔对《财富》杂志表示：“所有业内人士都有很大的动力来不断改进电池技术。这当然是特斯拉的命根子。”

    他说，特斯拉的Model X SUV备受期待，为此该公司必须提高电池容量。这是因为Model X较重，不提高电池容量的话，行驶里程就会缩短。

    布劳尔认为，特斯拉把精力集中在电池技术上不光是为了做出更好的汽车，它还想转型为供应商。

    许多公司都预计价格更低、性能更好的锂离子电池将投入使用，并且争相把这项技术用于民用和商用电网中。上述举措有可能让特斯拉成为这个新兴革命性能源行业中的领跑者。（财富中文网）

    译者: Charlie

    校对：詹妮

    An Electrode Particle Walks Into a Party

    Think of the battery electrode as a room and a lot of electrode particles—or people— are packed in there for a party, Dahn explains. Now imagine that everybody in that room suddenly becomes obese; the people aren’t going to fit anymore.

    “If everyone is already packed in there and they all become 400 pounds, you’re in big trouble,” says Dahn.

    This is what happens when all the particles in the electrode are silicon. But if only a few people in the room become obese, it’s not so bad because they can shuffle around and make enough space for these obese folks.

    “This is why only a small amount of silicon is being initially added,” Dahn says.

    That’s not the only issue with using silicon. To take the crowded room analogy a step further, imagine these obese people (or electrode particles) shrink when the battery is charged and then blow up again when it’s discharged. That enormous volume change causes another issue. The surface of every silicon particle is in contact with the electrolyte, and the protective film on the silicon is continually being stretched as the size of those particles change. When it shrinks it can flake off, which can impact the lifespan of the battery.

    This means that the more silicon you put in, the more challenging it is to maintain cycle life, Dahn says.

    Which brings us to where battery makers and researchers are today.

    “Right now, you put in a touch—a little pixie dust—and it’s tolerable,” says Dahn. “Over the years, more and more will go in and that’s a good thing because it means these products are going to improve and get better.”

    Dahn’s research team aims to increase both the energy density and the lifespan of lithium-ion cells, which could, in turn, help drive down costs in automotive and grid energy storage applications. They aren’t the only ones. “There are quite a few companies around the world that are starting to put silicon in the negative electrode,” explains Dahn. “And it’s not just Panasonic, Tesla’s supplier. Samsung and other companies around the world are doing this too.”

    Most batteries today, even those in consumer electronics, have tiny amounts of silicon, says Sam Jaffe, a longtime analyst, formerly of Navigant Research, and now CEO of startup Cygnus Energy Storage.

    The question is what percentage of silicon is Tesla using. The industry standard is between 1 to 3% silicon in battery recipes, Jaffe says. He believes Tesla has figured out how to use more.

    “For them to have made a significant change in the energy density of the battery and then to publicly say it’s the silicon increase makes me think—and this is speculation now—that they’ve made progress getting higher percentages of silicon into the cell,” Jaffe says.

    Model X and Tesla as a Supplier

    “There’s a lot of incentive to continue to improve this battery technology for everyone in the industry,” Karl Brauer, a senior analyst at Kelley Blue Book, told Fortune. “It’s certainly the lifeblood for Tesla.”

    Tesla had to increase the battery capacity for the highly anticipated Model X SUV because it’s heavier and without it, the vehicle would have lost range, Brauer says.

    Brauer also believes the focus on battery tech isn’t just to improve the cars, but to set the company up as a supplier.

    With many companies already anticipating the use of cheaper, more powerful lithium-ion batteries and competing to apply that technology to residential and commercial power grid applications, Tesla’s move could put them at the forefront of a newly revolutionized energy industry.